Zhihui made a homemade robotic arm that can sew stitches on grapes. It cost 10,000 yuan. Netizens asked: Can you open source your brain?

Jin Lei Xiaoxiao sent from Aofei Temple
Quantum Bit Report | Public Account QbitAI

On other people’s National Day, I built an Iron Man’s robotic arm!

It is still from the Huawei genius Zhihuijun , and it is still the most complex project he has ever done .

Come on, show it to Grape Stitch :

After the "grape bandage", the originally cracked wound became like this:

A key point:

All the above processes can be completed remotely and in real time in the toilet !

Its name is also very interesting - it is called Dummy .

But after all, Zhihui, who has the halo of "Wild Iron Man of Bilibili", said that this is his most complicated project (took 4 months) , and its hardcore level is certainly not limited to this.

The truth is that this robotic arm, inside and out, was all made by Zhihuijun!

(My friends, it’s another day when Zhihui breaks my defense)

So, naturally, netizens went crazy again with the barrage. Let’s feel this feeling (the whole screen is filled with “national quintessence”) :

Even people in the industry were amazed:

(Note: The content of this article has been authorized by Zhihuijun)

What a real robotic arm should look like

The robotic arm that Zhihui wants to build has multiple interaction methods.

For example, if you replace the end of the robotic arm with a "force feedback gripper" , it will instantly become a robotic arm that can grab potato chips:

In addition to the "force feedback gripper", if different effectors are used, the results that can be achieved will also be different:

• Install "laser" to achieve three-dimensional engraving

• Install "Paintbrush" and you can start painting and calligraphy

• Install a small "spindle" to use as a 6-axis engraving machine

And everything shown above is - synchronous reality !

In addition, Zhihuijun also created many different ways of interaction.

For example, combining it with cutting-edge technology, augmented reality (AR) - truly enabling the “point and shoot” effect.

There is also a way to open it through the teach pendant .

This teaching device was also designed by Zhihui. In his words:

Wherever I am, there is a screen.

This is the small wireless intelligent terminal designed by Zhihuijun, and it is also the "companion" of this robotic arm.

It can seamlessly connect to the robotic arm via low-power Bluetooth, and after the connection, it can display various status information of the robotic arm and switch various functions in real time.

Of course, Zhihui also did a more "earthly" graphical approach.

There are two more geeky methods: through the serial port and the command line .

How was such a wild Iron Man robotic arm “created”?

How to build Iron Man's robotic arm?

This cool-looking "hand" is a small high-precision 6-axis robotic arm .

Generally speaking, the construction of a robotic arm is mainly divided into four parts: robotic arm design, closed-loop servo, controller and spatial positioning device, which correspond to the robot's torso, heart, cerebellum and eyes respectively.

Robotic arm design refers to the "trunk" of the robot , which is a necessary step to enable the robot to move stably, including mechanical analysis, appearance design (3D modeling) , material selection, etc.

Of course, the design here is not that easy. There are more than 150 versions of the draft alone :

In order to ensure stability + cheapness and beauty, the final robot arm body was processed by aluminum CNC (numerical control) (to ensure stability) , and the decoration was produced by 3D printing (to save costs) .

Among them, the CNC part was made by Zhihuijun, who asked the UP host @XIKII who has a factory at home to help him make it. All 8 metal parts took a total of half a month:

The final design looks like this (Chinese Red & Iron Man Red) , and it looks pretty good:

The closed-loop servo , which is the "heart" of the robotic arm , is used to provide power for the robotic arm to work.

Specifically, the software includes FOC algorithm, absolute encoder & PID algorithm, CAN bus communication protocol and other parts. The hardware, in addition to the selection of materials such as motors, also includes details such as heat dissipation.

Normally, a robotic arm would use a brushless servo motor, but it is indeed quite large here.

Since Zhihui wanted to make a relatively small robot arm, he finally used a stepper motor with a 0 backlash harmonic reducer . The single drive effect looks like this:

Since it is a 6-axis robot, 6 stepper motors + 6 harmonic reducers are used as a whole, which together with software design form the "heart" of the robotic arm.

The controller refers to the "little brain" of the robotic arm , which is used to control the movements of the robotic arm and realize various functions.

In addition to mastering the principles of kinematics and dynamics analysis, additional "slash" skills such as circuit design, communication, and power management are also required in terms of software and hardware.

In fact, there are as many as 12 microcontroller units (MCUs) on this robotic arm .

The designs of the main controller (using redundant design) and the motor servo driver (supporting CAN bus & power machine connection) are as follows:

As for circuit design, it is more complicated than imagined. After all, in order to achieve the above-mentioned "multi-control" function, in addition to command line control, the relevant software and hardware of Bluetooth and wireless communication also need to be considered.

That's right, in addition to wired control, Bluetooth, WiFi , and 2.4G can also control this robotic arm~

Finally, there is the spatial positioning device , which is the "eye" of the robot arm , used to allow the robot arm to "see" and operate the tasks that need to be completed.

This includes our common binocular vision algorithm, AHRS system and force sensing system, all of which are completed in this step.

That’s right, the robotic arm designed by Zhihui is not just capable of performing simple operations such as “inputting tasks and completing them”, but is an “intelligent robotic arm” that can truly receive tasks from multiple angles and process them in real time.

Simply put, it uses binocular vision algorithm recognition, and then uses AI algorithm to achieve operations such as posture estimation:

After being mounted on the robotic arm, the "hand" can complete a series of complex operations based on human movements (the controller is modified from the PS5 handle):

Of course, after software de-shaking, motion range remapping, torque enhancement and other operations, the robotic arm can complete operations with higher precision than hands (good news for players with trembling hands) .

Finally, the software algorithms and hardware of these parts are assembled and debugged:

The final product looks like this, very smart:

So, what level can this robotic arm reach?

The cost is controlled within 10,000

As we all know, the price of robotic arms will rise rapidly as the accuracy increases.

A good quality industrial 6-axis robot with an accuracy of 0.6mm will cost tens of thousands of yuan , while the price of industrial robot arms from the four major families with an accuracy of about 0.02mm will directly rise to tens of thousands of dollars .

According to Zhihuijun's test results, the accuracy of the dial indicator with an accuracy of 0.01mm can directly reach about 0.02mm for end-point repeatability measurement :

With such precision, the robot should be expensive.

However, according to Zhihuijun, the overall hardware cost of Dummy is less than 10,000 yuan !

Of course, Zhihuijun also saved costs appropriately, including the harmonic reducer and the robot body, which are all second-hand ( if it is brand new hardware, the cost may be around 20,000 yuan) .

In addition, according to Zhihuijun, the size of this robotic arm itself is also very small, so the range of motion and precision are also correspondingly smaller and higher (there should be no robotic arm with such a small size and such high precision on the market currently) .

Where can such a robotic arm be used?

Imagine that if the accuracy continues to improve in the future, remote surgery may be possible:

Some netizens have also imagined the usage scenarios in more detail:

Even in remote areas, doctors from major hospitals can save lives simultaneously through remote surgery; or use intelligent program settings to perform simple operations such as skin suturing, saving doctors more time.

Regarding the project itself, some netizens joked that they would "open source their brains":

There are also some fantastic linkages in the technology area UP (manual dog head) :

Of course, we also know that Zhihuijun has joined "Huawei Genius Youth" at the end of last year.

In Zhihuijun's project, the operating system and AI computing platform also used Huawei Hongmeng and Ascend Atlas processors respectively .

Just on August 2, Ren Zhengfei praised Zhihui's project in his speech titled "Every generation has its own talents", pointing out that this is the driving force behind Huawei's innovation:

But for the 2012 Lab, the company never gave you too many restrictions. For example, someone was researching self-driving bicycles, and the company never restricted him.

Are we going to produce bicycles? No. This is a "scalpel" in his hands, and perhaps it will play a role in the future and generate huge commercial value.

Next, Zhihuijun plans to organize the project and open source it, and has already put a pit on GitHub.

Friends who are interested in making their own robotic arms can go and squat from time to time~

One More Thing

The project he produced this time is actually a birthday gift that Zhihui gave himself.

Here are my sincere birthday wishes~

Project address (to be sorted out):
https://github.com/peng-zhihui/Dummy-Robot

Zhihuijun robotic arm video (authorized):
https://www.bilibili.com/video/BV12341117rG

Reference link:
http://www.chinanews.com/business/2021/09-14/9565404.shtml